Exhaust system



FIG. 1 is a front perspective view of an exhaust system incorporating the new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side plan view thereof;

FIG. 5 is a right side plan view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a front elevational view thereof. 

The ornamental design for an exhaust system, as shown and described. 